teaching for long periods and back/shoulder pain

I sit in a chair next to the piano bench when I teach and occasionally will lean forward and point at a note for my student or to pencil something on their music. I also will use my right or left hand to play short passages while seated off to the side. I know that because I am not directly in front of the piano I create strange angles in my wrists but I do it anyway to save switching back and forth too much. This is not to say that I never sit at the bench, I do, it's just for those small passages or short problems that I'll play from the side. After a long day teaching, I have soreness between my shoulder blades and my shoulder itself. I stretch regularly and it helps, but I really want to just sit comfortably without all that leaning and extension. What do other teachers do to prevent this? I though about getting a laser pointer but figured it would be a distraction to have a red dot moving all over the music. Maybe a 4-foot pencil is the answer!! Thanks in advance for the help.

You might want to try educational catalogues/stores and look for something similar--
remember the metal chalk holders so you could draw a music staff on the board? I
remember watching an old film where the teacher actually drew a human figure using a
long pointer with a piece of chalk attached to it--this was filmed in one of those lecture
halls with the chalk boards that could be rolled up to the ceiling level so everyone could
see it from the back....

I have back problems too. I've found an office chair with wheels
helps me move back and forth a bit better. I purchased a long
pointer stick with an apple on the end of it. But the students
thought I'd hurt them. So that was pointless.

You can spend a little more time directing students verbally by
teaching them bar numbers and systems and beats.

Also include enough 15 minute breaks for yourself. And try
swimming to strengthen your back muscles.

If you can find a copy of Callanetics for Your Back, by Callan Pinckney (yes, of Callanetics
fame), there are several good, safe back exercises in it. It is out of print, but you can find
it in thrift stores, used book stores, and used on Amazon. Check if it is at your library, too.
If you have a separate (where you can close the door) office, you can keep an exercise mat
back there and take a break between students too.

She has some back exercises on one of the videos, I think. I'll check which one and post
back. I see now that all of her workouts are "exclusively from Amazon" on DVD now, but
the critiques have mentioned there's no chaptering, so if you can get a tape cheap, you
might as well.

One thing she recommends in the book is sitting in a rocking chair when you can. I saw in
Family Handyman a while back a hint to glue bicycle innertubes to the rockers so they
don't damage the floor.

Also, what about two copies of music, both with the measures numbered in pencil? That
would eliminate the pointing altogether.

Thanks for the input, I'll do more verbal direction using numbered
measures. I found yesterday I was more aware of each time I leaned
or reached, which by itself helped me to correct myself. I'll look
for those back exercises, too. If I refine my techniques enough, I
should be able to teach lying down on the couch with a bag of potato
chips and a pair of binoculars to see the students music! Just
kidding. KJ